Drupal Core has some pretty atrocious spelling errors in it.
Now, on one hand, we're geeks. Why would spelling matter?
However, as part of reaching a global audience, misspelled English words are a real affront to folks whose first language isn't English.
Finding text through search/replace is also more of a challenge when not all of the words are consistently used.
It also just looks pretty amateur. If this is an enterprise system, we can't be filled with lots of stupid typos in the code.
This is an issue to look specifically at the PHP errors.
Patch from #2329703-64: Spellchecking Drupal